Mixing Systems and Related Mixers

ABSTRACT

A mixing system includes a housing and a motor mount disposed on the housing and having a passage extending therethrough. A dive motor is coupled with the motor mount for selectively rotating the motor mount relative to the housing. A rotational assembly includes a hub having a passageway extending therethrough and a casing at least partially encircling the hub, the hub being rotatable to the casing. The rotational assembly is removably coupled to the housing so that the passageway of the hub aligns with the passage of the motor mount.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/112,834, filed Apr. 22, 2005 and claims priority to U.S.Provisional Application Ser. No. 60/784,403, filed Mar. 20, 2006, whichare incorporated herein by specific reference.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates to mixing systems that can be used in thebiopharmaceutical industry.

2. The Relevant Technology

The biopharmaceutical industry uses a broad range of mixing systems fora variety of processes such as in the preparation of media and buffersand in the growing of cells and microorganisms in bioreactors. Manyconventional mixing systems, including bioreactors, comprise a rigidtank that can be sealed closed. A drive shaft with impeller is rotatablydisposed within the tank. The impeller functions to suspend and mix thecomponents.

In many cases, great care must be taken to sterilize and maintain thesterility of the mixing system so that the culture or other product doesnot become contaminated. Accordingly, between the production ofdifferent batches, the mixing tank, mixer, and all other reusablecomponents that contact the processed material must be carefully cleanedto avoid any cross contamination. The cleaning of the structuralcomponents is labor intensive, time consuming, and costly. For example,the cleaning can require the use of chemical cleaners such as sodiumhydroxide and may require steam sterilization as well. The use ofchemical cleaners has the additional challenge of being relativelydangerous, and cleaning agents can be difficult and/or expensive todispose of once used.

The operation and maintenance of such mixing systems can be daunting formany facilities, especially where it is desirable to make a large numberof smaller batches. Accordingly, what is needed are mixing systems thatrequire minimum cleaning or sterilization, can be used for mixing orsuspending a broad range of materials, can consistently provide asterile environment, and are relatively inexpensive and easy to operate.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention will now be discussed withreference to the appended drawings. It is appreciated that thesedrawings depict only typical embodiments of the invention and aretherefore not to be considered limiting of its scope.

FIG. 1 is a perspective view of one embodiment of an inventive mixingsystem;

FIG. 2A is a perspective view of a mixer with closed container that canbe used as part of the mixing system depicted in FIG. 1;

FIG. 2B is a perspective view of a mixer with open container that can beused with the mixing system depicted in FIG. 1;

FIG. 3 is a partially exploded perspective view of the mixer shown inFIGS. 2A and 2B;

FIG. 4 is a cross sectional side view of a motor mount of the mixershown in FIG. 3;

FIG. 5 is a top perspective view of the housing shown in FIG. 3 havingthe motor mount of FIG. 4 secured thereto;

FIG. 6 is a partially exploded side view of a drive rod and impellerassembly shown in FIG. 3;

FIG. 7 is an enlarged perspective view of a head section of the driveshaft shown in FIG. 6;

FIG. 8 cross sectional side view of a rotational assembly shown in FIG.6;

FIG. 9 is a cross sectional side view of the impeller and connectorshown in FIG. 6;

FIG. 10 is an enlarged perspective view of the housing and rotationalassembly shown in FIG. 3;

FIG. 11 is a side view of the rotational assembly shown in FIG. 10coupled with the housing;

FIG. 12 is a perspective view of the drive shaft being coupled with themotor mount; and

FIG. 13 is a perspective view of an alternative mixer with opencontainer that can be used with the mixing system depicted in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to mixing systems that are primarilydesigned for use in the biopharmaceutical industry but can also haveapplicability in a wide variety of other industries. By way of example,the mixing systems disclosed herein can be used as a single usebioreactor for growing cells, microorganisms, and other biologicalcultures. The mixing systems can also be used for hydrating powders,such as in the production of media or buffers, and in the manufacturing,treating, and/or processing of a wide variety of other liquid basedproducts.

The inventive mixing systems can be used in sterile or non-sterileprocessing and are designed so that a majority of the system componentsthat contact the material being processed can be disposed of after eachuse. As a result, the inventive mixing systems substantially eliminatethe burden of cleaning and sterilization required by conventionalstainless steel mixing systems. This feature also ensures that sterilitycan be consistently maintained during repeated processing of multiplebatches. In view of the foregoing, and the fact that the inventivesystems are easily scalable, relatively low cost, and easily operated,the inventive mixing systems can be used in a variety of industrial andresearch facilities that previously outsourced such processing.

It is noted that the inventive mixing systems disclosed herein representimprovements and/or modifications to the mixing systems previouslydisclosed in U.S. patent application Ser. No. 11/112,834, filed Apr. 22,2005 (“the '834 application”) that is hereby incorporated by specificreference. As such, further disclosure with regard to the inventivemixing systems disclosed herein and their corresponding components anduses, along with related alternative embodiments, can be found in the'834 application.

Depicted in FIG. 1 is one embodiment of an inventive mixing system 10incorporating features of the present invention. In general, mixingsystem 10 comprises a rigid support housing 12 having an interiorsurface 14 that extends between a lower end 16 and an upper end 18.Interior surface 14 bounds a compartment 20. An annular lip 22 is formedat upper end 18 and bounds an opening 24 to compartment 20. Lower end 16of support housing 12 rests on a cart 26 having wheels 28. Cart 26enables selective movement and positioning of mixing system 10. Inalternative embodiments support housing 12 can be fixed at a designatedlocation.

Although support housing 12 is shown as having a substantiallycylindrical configuration, in alternative embodiments support housing 12can have any desired shape capable of at least partially bounding acompartment. Furthermore, it is appreciated that support housing 12 canbe scaled to any desired size. For example, it is envisioned thatsupport housing 12 can be sized so that compartment 20 can hold a volumeof less than 50 liters or more than 1,000 liters. Support housing 12 istypically made of metal, such as stainless steel, but can also be madeof other materials capable of withstanding the applied loads of thepresent invention.

Mixing system 10 also comprises a mixer 30 coupled with a supporthousing 12 by a bracket 31. Depicted in FIG. 2A, mixer 30 is shown beingcoupled with a container 32. Container 32 bounds a compartment 34 inwhich a portion of mixer 30 is disposed. In the embodiment depicted,container 32 comprises a flexible bag. Although not illustrated, it isappreciated that container 32 can be formed with or connected to avariety of ports, probes, secondary containers, spargers, and/or otherfittings at various locations depending on the intended use for mixingsystem 10. Examples of such ports and attachments are disclosed in the'834 application and in the United States Patent Application entitled“Gas Sparger and Related Container Systems” filed Mar. 20, 2006 in thename of Michael E. Goodwin et al. and in the United States PatentApplication entitled “Tube Ports and Related Container Systems” filedMar. 20, 2006 in the name of Michael E. Goodwin et al., whichapplications are incorporated herein by specific reference.

In the depicted embodiment, container 32 has an opening 36 that issealed to a rotational assembly 38 that will be discussed below ingreater detail. As a result, compartment 34 is sealed closed so that itcan be used in processing sterile fluids. In contrast, in the embodimentdepicted in FIG. 2B, mixer 30 operates with a container 40 thatpartially bounds a compartment 42. Container 40 comprises a flexibleopen top liner. That is, container 40 has an annular lip 44 that boundsan exposed opening 46 to compartment 42. Container 40 is thus used inthe processing of non-sterile fluids.

During use, both containers are disposed within chamber 20 of supporthousing 12 depicted in FIG. 1. The containers are supported by supporthousing 12 during use and can subsequently be disposed of following use.In one embodiment, the containers are comprised of a flexible, waterimpermeable material such as a low-density polyethylene or otherpolymeric sheets having a thickness in a range between about 0.1 mm toabout 5 mm with about 0.2 mm to about 2 mm being more common. Otherthicknesses can also be used. The material can be comprised of a singleply material or can comprise two or more layers which are either sealedtogether or separated to form a double wall container. Where the layersare sealed together, the material can comprise a laminated or extrudedmaterial. The laminated material comprises two or more separately formedlayers that are subsequently secured together by an adhesive.

The extruded material comprises a single integral sheet that comprisestwo or more layers of different materials that can be separated by acontact layer. All of the layers are simultaneously co-extruded. Oneexample of an extruded material that can be used in the presentinvention is the HyQ CX3-9 film available from HyClone Laboratories,Inc. out of Logan, Utah. The HyQ CX3-9 film is a three-layer, 9 mil castfilm produced in a cGMP facility. The outer layer is a polyesterelastomer coextruded with an ultra-low density polyethylene productcontact layer. Another example of an extruded material that can be usedin the present invention is the HyQ CX5-14 cast film also available fromHyClone Laboratories, Inc. The HyQ CX5-14 cast film comprises apolyester elastomer outer layer, an ultra-low density polyethylenecontact layer, and an EVOH barrier layer disposed therebetween. In stillanother example, a multi-web film produced from three independent websof blown film can be used. The two inner webs are each a 4 mil monolayerpolyethylene film (which is referred to by HyClone as the HyQ BM1 film)while the outer barrier web is a 5.5 mil thick 6-layer coextrusion film(which is referred to by HyClone as the HyQ BX6 film).

The material is approved for direct contact with living cells and iscapable of maintaining a solution sterile. In such an embodiment, thematerial can also be sterilizable such as by ionizing radiation.Examples of materials that can be used in different situations aredisclosed in U.S. Pat. No. 6,083,587 which issued on Jul. 4, 2000 andU.S. Patent Publication No. U.S. 2003-0077466 A1, published Apr. 24,2003 which are hereby incorporated by specific reference.

In one embodiment, the containers comprise a two-dimensional pillowstyle bag wherein two sheets of material are placed in overlappingrelation and the two sheets are bounded together at their peripheries toform the internal compartment. Alternatively, a single sheet of materialcan be folded over and seamed around the periphery to form the internalcompartment. In another embodiment, the containers can be formed from acontinuous tubular extrusion of polymeric material that is cut to lengthand is seamed closed at the ends.

In still other embodiments, the containers can comprise athree-dimensional bag that not only has an annular side wall but also atwo dimensional top end wall and a two dimensional bottom end wall.Three dimensional containers comprise a plurality of discrete panels,typically three or more, and more commonly four or six. Each panel issubstantially identical and comprises a portion of the side wall, topend wall, and bottom end wall of the container. Corresponding perimeteredges of each panel are seamed. The seams are typically formed usingmethods known in the art such as heat energies, RF energies, sonics, orother sealing energies.

In alternative embodiments, the panels can be formed in a variety ofdifferent patterns. Further disclosure with regard to one method ofmanufacturing three-dimensional bags is disclosed in U.S. PatentPublication No. U.S. 2002-0131654 A1 that was published Sep. 19, 2002 ofwhich the drawings and Detailed Description are hereby incorporated byreference.

It is appreciated that the containers can be manufactured to havevirtually any desired size, shape, and configuration. For example, thecontainers can be formed having a compartment sized to 10 liters, 30liters, 100 liters, 250 liters, 500 liters, 750 liters, 1,000 liters,1,500 liters, 3,000 liters, 5,000 liters, 10,000 liters or other desiredvolumes. Although the containers can be any shape, in one embodiment thecontainers are specifically configured to be complementary orsubstantially complementary to chamber 20 of support housing 12.

In any embodiment, however, it is desirable that when the containers arereceived within chamber 20, the containers are uniformly supported bysupport housing 12. Having at least generally uniform support of thecontainers by support housing 12 helps to preclude failure of thecontainers by hydraulic forces applied to the containers when filledwith fluid.

Although in the above discussed embodiment the containers have aflexible, bag-like configuration, in alternative embodiments it isappreciated that the containers can comprise any form of collapsiblecontainer or semi-rigid container. The containers can also betransparent or opaque and can have ultraviolet light inhibitorsincorporated therein.

Turning to FIG. 3, mixer 30 comprises a housing 54 having a front face56 that extends between a top surface 58 and an opposing bottom surface60. Front face 56 also extends between a first side 62 and an opposingsecond side 64. An opening 66 extends through housing from top surface58 to bottom surface 60.

A motor mount 70 is rotatably secured within opening 66 of housing 54.As depicted in FIGS. 4 and 5, motor mount 70 has an interior surface 72and an exterior surface 74 each extending between a first end 76 and anopposing second end 78. First end 76 terminates at a first end face 80while second end 78 terminates at a second end face 82. Motor mount 70generally comprises an elongated substantially cylindrical stem 84formed at second end 78 and an enlarged radially outwardly projectingflange 86 formed at first end 76. Engagement threads 88 radiallyencircle the side wall of flange 86. As will be discussed below ingreater detail, a locking pin 90 outwardly projects from a top surfaceof flange 86.

Interior surface 72 of motor mount 70 bounds a passage 92 that extendsbetween end faces 80 and 82. Interior surface 72 includes asubstantially cylindrical transition portion 94 that extends along thelength of stem 84 and a substantially frustoconical engaging portion 96that extends along flange 86. As will be discussed below in greaterdetail, the configuration of engaging portion 96 helps facilitate propercentering of the drive shaft and helps minimize or eliminate fretcorrosion.

Returning to FIG. 3, a drive motor 100 is mounted on side 64 of housing54. Drive motor 100 engages with stem 84 of motor mount 70 so as tofacilitate select rotation of motor mount 70 relative to housing 54.

A drive shaft 110 is configured to pass through passage 92 of motormount 70 and thus through housing 54. Turning to FIG. 6, drive shaft 110comprises a head section 112 and a shaft section 114 that are connectedtogether. As depicted in FIG. 7, head section 112 has an exteriorsurface 115 extending between a first end 116 and an opposing second end118. First end 116 terminates at a first end face 120 while second end118 terminates at a second end face 122. Recessed into second end face122 is a threaded socket 124. Head section 112 is comprised of aconnecting portion 126 extending back from second end face 122. As willbe discussed below in greater detail, connecting portion 126 has anoncircular transverse cross section so that it can facilitate lockingengagement with another structure. In the embodiment depicted,connection portion 126 has a polygonal transverse cross section.However, other noncircular shapes can also be used.

Extending back from connecting portion 126 is a substantiallycylindrical central portion 128 head section 112. Extending from centralportion 128 substantially frustoconical engaging portion 130. Engagingportion 130 has a configuration complimentary to frustoconical engagingportion 96 of motor mount 70 so that engaging portions 96 and 130 can becomplementary mated to facilitate contacting engagement between motormount 70 and drive shaft 110.

Finally, a substantially circular plate section 132 extends betweenengaging portion 130 and first end face 120. Plate section 132 extendsto a perimeter edge 134 that radially outwardly projects beyond engagingportion 130. A plurality of spaced apart notches 136 are formed onperimeter edge 134. As will be discussed below in greater detail,notches 136 are designed to receive locking pin 90 of motor mount 70.

Returning to FIG. 6, shaft section 114 of drive shaft 110 has a firstend 140 and an opposing section end 142. First end 140 terminates at aterminus 144 having encircling threads 146 formed thereat. Terminus 144is configured to be threadedly received within socket 124 of headsection 112 so as to rigidly secure head section 112 to shaft section114, thereby forming drive shaft 110. In alternative embodiments, it isappreciated that there are a variety of alternative connectiontechniques that can be used to secure head section 112 to drive section114. For example, the structures can be connected together by press fit,welding, adhesive, clamps, or other conventional fasteners. Theassembled drive shaft 110 thus extends between first end 116 and secondend 142. Second end 142 of shaft section 114 ends at a terminus 148having a noncircular transverse cross section. That is, as withconnecting portion 128 head section 112 previously discussed, terminus148 is configured to couple with another structure as is discussed belowin great detail such that rotation of drive shaft 110 facilitiesrotation of the structure. In this regard, terminus 148 can have anynoncircular transverse cross section. In the embodiment depicted,terminus 148 has a polygonal transverse cross section althoughelliptical, irregular, and other noncircular transverse cross sectionswill also work.

In one embodiment, head section 112 and shaft section 114 are made ofdifferent materials. By way of example and not by limitation, in oneembodiment head section 112 can be made of a polymeric material such asa polyacetal material, nylon, or polypropylene. One preferred type ofpolyacetal material is sold under the trademark DELRIN®. In alternativeembodiments, however, head section 112 can also be made of ceramics,composites, metals, such as aluminum, stainless steel, other metalalloys, or other materials. Shaft section 114 can also be made of any ofthe materials as discussed above. However, in one typical embodiment,head section 112 is made of DELRIN® while shaft section 114 is made ofaluminum. As will be discussed below in greater detail, thisconfiguration minimizes costs while helping to minimize or eliminatefret corrosion. In still other embodiments, it is appreciated that driveshaft 110 can be made as a single integral member entirely formed fromthe same material. That is, all of drive shaft 110 can be made of allthe same alternative materials as previously discussed above with regardto head section 112.

As also depicted in FIG. 6, mixer 30 further comprises an impellerassembly 160. Impeller assembly 160 comprises rotational assembly 38, anelongated connector 162, and an impeller 164. As depicted in FIG. 8,rotational assembly 38 comprises a hub 168 that is partially encircledby a casing 170. Hub 168 comprises an elongated stem 172 having aninterior surface 174 and an exterior surface 176 each extending betweena first end 178 and an opposing section end 180. Encircling and radiallyoutwardly projecting from exterior surface 176 between opposing ends 178and 180 is a support flange 182. Encircling and radially outwardlyprojecting from second end 180 of stem 172 is an annular barb 184.

Interior surface 174 bounds a passage 175 that extends through stem 172.Interior surface 174 includes a connecting portion 186 formed at firstend 178. Connecting portion 186 has a noncircular transverse crosssection that is complementary to the transverse cross section ofconnecting portion 126 of drive shaft 110. Accordingly, when connectingportion 126 of drive shaft 110 is received within connecting portion 186of hub 168, drive shaft 110 engages hub 168 that rotation of drive shaft110 facilitates complementary rotation of hub 168. It is appreciatedthat there are a variety of complementary configurations that can beused by connection portions 126 and 186. Furthermore, connectingportions 126 and 186 need not be completely complementary but merelyconfigured such that connecting portion 126 interlocks with connectingportion 186. In still other embodiments, it is appreciated that otherfasteners or connecting techniques can be used to engage drive shaft 110to hub 168.

In the depicted embodiment, the remainder of interior surface 174 of hub168, extending between connecting portion 186 and second end 180, has asubstantially cylindrical transverse cross section. In alternativeembodiments, however, this remainder of interior surface 174 can be anydesired transverse cross section that will allow drive shaft 110 to passtherethrough. For example, if desired, all of interior surface 174 canhave the same transverse cross section as connecting portion 186.

As also depicted in FIG. 8, casing 170 has an interior surface 190 andan exterior surface 192 extending between a first end 194 and anopposing second end 196. Formed at first end 194 is an annular collar198. An annular support flange 200 encircles and radially outwardlyprojects from collar 198. Casing 170 further comprises an annularsealing flange 202 formed at second end 196. Sealing flange 202 has atop surface 204 against which container 32 can be sealed, such as bywelding or other conventional techniques as illustrated in FIG. 2A.Extending between sealing flange 202 and collar 198 are two annularshoulders 206 and 208 consecutively inwardly step. Interior surface 190of casing 170 bounds an opening 210 extending through casing 170. Hub168 rotatably disposed within opening 210 so that hub 168 can rotaterelative to casing 170. To facilitate ease in rotation, a pair ofbearing assemblies 212 encircle hub 168 and extend between hub 168 andcasing 170. Furthermore, a plurality of seals 214 are disposed withinopening 210 so as to form a liquid type seal between hub 168 and casing170.

Finally, a first retainer 216 encircles hub 168 at first end 178 while asecond retainer 218 circles hub 168 toward second end 180. Retainers 216and 218 are disposed within opening 210 and extend between hub 168 andcasing 170 so as to secure hub 168 within casing 170 and to support andmaintain bearing assemblies 212 and seals 214 within opening 210. Aswith the other components of mixing system 10 disclosed herein, it isnoted that a variety of alternative designs for rotational assembly edisclosed in the '834 application.

Returning to FIG. 6, casing 162 is an elongated tubular member having anexterior surface 224 and an interior surface 226 (FIG. 9) extendingbetween a first end 228 and an opposing second end 230. Interior surface226 bounds a passage 232 that extends through connector 162 along thelength thereof. Connector 162 can be made out of a variety of rigid orflexible materials such as metals, plastics, composites, or others.Connector 162, however, is typically not subject to any significantloads and primarily functions as a seal for drive shaft 110. As such, tominimize expense, connector 162 is typically made from a flexiblepolymeric material such as that used in conventional tubing. Thisfurther enables connector 162 to be coiled, bent, or folded duringsterilization, transport, and/or storage so as to minimize space.Connector 162 is coupled with rotational assembly 38 inserting secondend 180 of hub 168 into passage 232 of connector 162 at first end 2228thereof. A plastic pull tie, clamp, crimp, or other fastener can then becinched around first end 228 so as to form a liquid tight sealedengagement between hub 168 and connector 162.

As also depicted in FIG. 6 and in FIG. 9 with greater detail, impeller164 comprises a central hub 240 having a plurality of fins 242 radiallyoutwardly projecting therefrom. Hub 240 has a first end 244 with acavity 246 recessed in thereat. An insert 248 is received within cavity246 and bounds an open socket 250. Socket 250 has a noncirculartransverse cross section that is complementary to terminus 148 of driveshaft 110 (FIG. 6). Accordingly, as will be discussed below in greaterdetail, when terminus 148 is received within socket 250, terminus 148gages with impeller 164 such that rotation of drive shaft 110 facilitiesrotation of impeller 164. It is again appreciated that terminus 148 andsocket 250 can have a variety of alternative complementary orinterlocking configurations that enable engagement between terminus 148drive shaft 110 and impeller 164. Alternative press fit and mechanicalfastening techniques can also be used.

In one embodiment, hub 240 and fins 242 of impeller 164 are molded froma polymeric material while insert 248 formed from a metallic material.In alternative embodiments, hub 240 and fins 242 can be made of metal,composite, or a variety of other materials. Furthermore, insert 248 canbe eliminated in that cavity 246 can be configured to form socket 250.

Impeller 164 is attached to connector 162 by inserting first end 244 ofhub 240 within passage 232 of connector 162 at second end 230. A pulltie clamp, crimp, or other type of fastener can then be cinched aroundsecond end 230 of connector 162 so as to form a liquid tight sealedengagement between impeller 164 and connector 162.

Either prior to or following the complete assembly of impeller assembly160 as discussed above, container 32 is sealed to sealing flange 202 asdepicted in FIG. 2A. In this assembled state, compartment 34 ofcontainer 32 is sealed closed. The assembled impeller assembly 160 andcontainer 32 is a disposable unit that when in the assembled state canbe sterilized by conventional processes such as radiation. Again,because of the flexible nature of connector 162 and container 32,container 32 can be collapsed and folded into a compact state forsterilization, transport, and storage. Depending on its intended use,various ports, tubes, probes, secondary containers and the like can bemounted on or connected to container 32 prior to or subsequent tosterilization of container 32.

During use, container 32 is positioned within chamber 20 of supporthousing 12. Rotational assembly 38 then connected to housing 54 of mixer30. Turning to FIG. 10, housing 54 has an open access 260 that isrecessed on front face 56 so as to communicate with opening 66 extendingthrough housing 54. Access 260 is in part bounded by a substantiallyC-shaped first side wall 262 that extends up from bottom surface 60, aconcentrically disposed substantially C-shaped second side wall 264disposed above first side wall 262 and having a diameter larger thanfirst side wall 262, and a substantially C-shaped shoulder 266 extendingbetween side walls 262 and 264. As shown in FIGS. 2A and 11, a door 268is hingedly mounted to housing 54 and selectively closes the opening toaccess 260 from front face 56. Door 262 is secured in a closed positionby a latch 270. Positioned on first side wall 262 is a section 272 of aresilient and/or elastomeric material such as silicone. Other sections272 of similar materials can also be positioned on first side wall 262or the interior surface of door 268.

To facilitate attachment of rotational assembly housing 54, with door268 rotated to an open position, rotational assembly horizontally slidinto access 260 from front face 56 of housing 54 so that support flange200 of rotational assembly 38 rests on shoulder 266 of access 260.Rotational assembly advanced into access 260 so that passage 175extending through hub 168 of rotational assembly 38 aligns with passage92 of motor mount 70 (FIG. 4). In this position, door 268 is moved tothe closed position and secured in the closed position by latch 270. Asdoor 268 is closed, casing 170 of rotational assembly 38 is biasedagainst the one or more sections 272 of resilient material so as toclamp rotational assembly 38 within access 260 and thereby preventunwanted rotational movement of casing 170 relative to housing 54.

Once rotational assembly 38 is secured to housing 54, second end 142 ofthe assembled drive shaft 110 is advanced down through passage 92 ofmotor mount 70 depicted in FIG. 5. Second end 142 of drive shaft 110passes down through motor mount 70, through passage 175 of hub 168 ofrotational assembly 38, and through passage 232 of connector 162.Finally, terminus 148 of drive shaft 110 is received within socket 250of impeller 164. Again, because of the complimentary transversepolygonal configurations of socket 250 and terminus 148, drive shaft 110engages impeller 164 such that rotation of drive shaft 110 facilitatesrotation of impeller 164. With terminus 148 received in socket 250,connecting portion 126 of drive shaft 110 is received within connectingportion 186 of hub 168. Again, the complimentary interlockingconfigurations of connection portion 126 and 186 cause hub 168 to rotateas drive shaft 110 is rotated. Furthermore, because casing 170 issecured to housing 54, hub 168 rotates relative to casing 170 andhousing 54 as drive shaft 110 is rotated. It is further noted thatconnector 162 also rotates concurrently with impeller 164, hub 168 anddrive shaft 110.

Finally, with reference to FIG. 12, once drive shaft 110 is fully passedthrough motor mount 70, drive shaft 110 is oriented so that locking pin90 of motor mount 70 is received within a corresponding notch 136 ofdrive shaft 110. Accordingly, as motor 100 facilitates rotation of motormount 70, locking pin 90 concurrently rotates with motor mount 70, whichin turn biases against the interior surface of notch 136 so as tofacilitate rotation of drive shaft 110. In turn, as discussed below ingreater detail, rotation of drive shaft 110 facilitates rotation of hub168, connector 162 and impeller 164. Rotation of impeller 164 facilitiesmixing of the fluid within compartment 34 of container 32 or compartment42 of container 40.

Locking pin 90 and notches 136 are only one example of how drive shaft110 and motor mount 70 can coupled together. It is appreciated that anytype of fastener, pin, clamp, keyway or other engaging structure thatwill couple drive shaft 110 and motor mount 70 together so that rotationof motor mount 70 will rotate draft shaft 100 will work.

Further, with drive shaft 110 received within motor mount 70,frustoconical engaging portion 130 of drive shaft 110 is received withinfrustoconical engaging portion 96 of motor mount 70. Engaging portions130 and 96 have complementary configurations so that a close tolerancefit is formed therebetween. The frustoconical configuration of engagingportions 130 and 96 help to facilitate proper centering of drive shaft110 on motor mount 70. Furthermore, the repeated rotation of drive shaft110 and impeller 164 produces micro vibrations on drive shaft 110. Theclose tolerance fit between engagement portions 130 and 96 helps toprevent fret corrosion between drive shaft 110 and motor mount 70.

To further decrease fret corrosion, it is preferable that engagingportions 130 and 96 be formed from different materials. Accordingly, inone embodiment head section 112 of drive shaft 110 is formed from apolymeric material whereas motor mount 70 is formed from metal such asstainless steel, aluminum, or the like. In yet other embodiments,various combinations of different materials can be used.

In one embodiment of the present invention, means are provided forselectively rotating drive shaft 110. One example of such meanscomprises housing 54, drive motor 100, and motor mount 70 as discussedabove. Alternative embodiments of such means comprise the alternativesto drive shaft 100, housing 54, drive motor 100, and motor mount 70 asdiscussed herein. Further alternatives of such means comprise thealternative systems for rotating the drive shaft as discussed in the'834 application. In still other embodiments, it is appreciated that avariety of other well known keyways, gearing, belt systems, and the likecan be used in rotating drive shaft 100.

Returning to FIG. 3, once drive shaft 110 is properly seated on motormount 70, a retention cap 276 is threaded onto first end 76 of motormount 70 so as to prevent drive shaft 110 from unintentionallydisengaged from motor mount 70. A further safety cap 278 is secured totop surface 58 housing 54 so as to cover retention cap 276 as depictedin FIG. 1.

Once a material is processed and removed from container 32 or 40, theimpeller assembly 160 and corresponding containers can be removed anddisposed of. A new container and impeller assembly 160 can then be usedfor the next batch. Since drive shaft 110 and the rest of the mixingsystem does not contact the processed material, no cleaning orsterilization is required.

As previously discussed, various alternatives for the differentcomponents of mixing system 10 and mixer 30 are disclosed in the '834patent. As such, the various components between the different referencescan be mixed and matched to obtain a variety of other alternativeembodiments.

Returning to FIG. 2B, as previously discussed, in this embodiment mixer30 operates with container 40 that is an open top liner. That is, incontrast to annular lip 44 of container 40 being sealed to sealingflange 202 of rotational assembly 38, annular lip 44 is freely exposedso as to expose opening 46 to compartment 42. Container 40 can bedisposed and supported within support housing 12. The aboveconfiguration can be used as a lower cost alternative for mixingnon-sterile fluids. In this embodiment, rotational assembly 38 merelyfunctions to secure first end 228 connector 162 to housing 54 so thatconnector 162 does not unintentionally slide off of drive shaft 110. Inalternative embodiments, because rotational assembly 38 is no longerforming a sealed fluid connection between container 40 and connector162, rotational assembly 38 can be substantially simplified. Forexample, sealing flange 202 and the various seals 214, depicted in FIG.8, can be eliminated.

Depicted in FIG. 13 is a further simplified embodiment of mixer 30. Inthis embodiment, rotational assembly completely eliminated. A clamp 290is removably disposed at first end 228 of connector 162 so as totemporarily secure first end 228 of connector 162 to drive shaft 110.That is, clamp 290 can be mounted on tubular connector 162 so as toradially inwardly bias tubular connector 162 directly against driveshaft 110, thereby securing tubular connector 162 to drive shaft 110.

Clamp 290 can come in a variety of alternative configurations. Forexample, clamp 290 can comprise a conventional mechanical clamp, hoseclamp, plastic pull tie, removable crimp, or any other type of fastenerthat can bias connector 162 to drive shaft 110 to prevent connector 162and impeller 164 from unintentionally sliding off of drive shaft 110. Inone embodiment of the present invention, means are provided for securingfirst end 228 of tubular connector 162 to drive shaft 110. One exampleof such means comprise clamp 290 and the alternative embodimentsdiscussed therewith. Once processing and use of a batch is complete,clamp 290 is removed and connector 162 and impeller 164 can be disposedof along with container 40. Replacement parts can then be used forsubsequent batches.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. A mixing system comprising: a housing; a motor mount disposed on thehousing and having a passage extending therethrough; a drive motorcoupled with the motor mount for selectively rotating the motor mountrelative to the housing; and a rotational assembly comprising a hubhaving a passageway extending therethrough and a casing at leastpartially encircling the hub, the hub being rotatable relative to thecasing, the rotational assembly being removably coupled to the housingso that the passageway of the hub aligns with the passage of the motormount.
 2. The mixing system as recited in claim 1, further comprising:an access recessed on the housing, at least a portion of the accessbeing bounded by a shoulder; and the casing of the rotational assemblyhaving a flange formed thereon, the rotational assembly being removablyreceived within the access of the housing so that the flange of thecasing rests on the shoulder of the access.
 3. The mixing system asrecited in claim 2, wherein the housing comprises a door that can beselectively closed so as to clamp the rotational assembly within theaccess of the housing.
 4. The mixing system as recited in claim 3,further comprising a section of resilient elastomeric material lining aportion of the access, the rotational assembly biasing against theelastomeric material when the door is closed.
 5. The mixing system asrecited in claim 1, further comprising: an elongated tubular connectorhaving a first end and an opposing second end, the first end of theconnector being connected to the hub; and an impeller at the second endof the tubular connector.
 6. The mixing system as recited in claim 5,further comprising a container having a compartment, the impeller beingdisposed within the compartment.
 7. The mixing system as recited inclaim 6, wherein the container comprises a flexible bag secured to thecasing of the rotational assembly.
 8. The mixing system as recited inclaim 6, wherein the container comprises a flexible liner having an openmouth, the connector extending through the open mouth.
 9. The mixingsystem as recited in claim 5, further comprising a drive shaft having afirst end and an opposing second end, the second end of the drive shaftbeing passed through the motor mount, through the hub of the rotationalassembly, and through the connector so that the second end of the driveshaft engages with the impeller.
 10. The mixing system as recited inclaim 9, wherein the first end of the drive shaft engages with the motormount so that rotation of the motor mount by the drive motor facilitatesrotation of the drive shaft.
 11. The mixing system as recited in claim9, further comprising: the first end of the drive shaft having a firstengaging portion with a substantially frustoconical configuration; andthe motor mount having an interior surface bounding the passageextending therethrough, a least a portion of the interior surfaceforming a second engaging portion having a substantially frustoconicalconfiguration complementary to the first engaging portion, the firstengaging portion being received within the second engaging portion. 12.The mixing system as recited in claim 11, wherein one of the firstengaging portion and the second engaging portion is comprised of apolymeric material and the other of the first engaging portion and thesecond engaging portion is comprised of a metal.
 13. A mixing systemcomprising: a motor mount having a passage extending therethrough; adrive motor coupled with the motor mount for selectively rotating themotor mount; a container having a compartment; and a drive shaft havinga first end and an opposing second end, the first end of the drive shafthaving a first engaging portion with a substantially frustoconicalconfiguration, the drive shafted being passed through the passage of themotor mount so that the first engaging portion of the drive shaft is atleast partially disposed within the passage of the motor mount and thesecond end of the drive shaft is disposed within the compartment of thecontainer.
 14. The mixing system as recited in claim 13, the motor mounthaving an interior surface bounding the passage extending therethrough,at least a portion of the interior surface forming a second engagingportion having a substantially frustoconical configuration complementaryto the first engaging portion, the first engaging portion being receivedwithin the second engaging portion.
 15. The mixing system as recited inclaim 14, wherein one of the first engaging portion and the secondengaging portion is comprised of a polymeric material and the other ofthe first engaging portion and the second engaging portion is comprisedof a metal.
 16. The mixing system as recited in claim 13, wherein thedrive shaft comprises: a head section that includes the first engagingportion, the head section being comprised of a polymeric material; and ashaft section that includes the second end of the drive shaft, the shaftsection being comprised of a metal, the head section and the shaftsection being connected together.
 17. The mixing system as recited inclaim 13, further comprising: a housing; and a rotational assemblycomprising a hub having a passageway extending therethrough and a casingat least partially encircling the hub, the hub being rotatable relativeto the casing, the rotational assembly being removably coupled to thehousing so that the passageway of the hub aligns with the passage of themotor mount.
 18. The mixing system as recited in claim 17, furthercomprising: an access recessed in the housing, at least a portion of theaccess being bounded by a shoulder; and the casing of the rotationalassembly having a flange formed thereon, the rotational assembly beingremovably received within the access of the housing so that the flangeof the casing rests on the shoulder of the access.
 19. The mixing systemas recited in claim 18, wherein the housing comprises a door that can beselectively closed so as to clamp the rotational assembly within theaccess of the housing.
 20. The mixing system as recited in claim 17,wherein the motor mount is rotatably coupled with the housing.
 21. Themixing system as recited in claim 17, further comprising: an elongatedtubular connector having a first end and an opposing second end, thefirst end of the connector being connected to the hub; and an impellerat the second end of the tubular connector.
 22. The mixing system asrecited in claim 21, further comprising a container having acompartment, the impeller being disposed within the compartment.
 23. Themixing system as recited in claim 22, wherein the container comprises aflexible bag secured to the casing of the rotational assembly.
 24. Themixing system as recited in claim 22, wherein the container comprises aflexible liner having an open mouth, the connector extending through theopen mouth.
 25. The mixing system as recited in claim 21, wherein thesecond end of the drive shaft is passed through the motor mount, throughthe hub of the rotational assembly, and through the connector so thatthe second end of the drive shaft engages with the impeller.
 26. Themixing system as recited in claim 25, wherein the first end of the driveshaft engages with the motor mount so that rotation of the motor mountby the drive motor facilitates rotation of the drive shaft.
 27. Themixing system as recited in claim 25, wherein the drive shaft engagesthe hub so that rotation of the drive shaft facilitates rotation of thehub relative to the casing.
 28. A method comprising: removably couplinga rotational assembly to a housing, the rotational assembly comprising ahub having a passageway extending therethrough and a casing at leastpartially encircling the hub, the hub being rotatable relative to thecasing, an elongated tubular connector having a first end connected tothe hub and an opposing second end with an impeller positioned thereat;advancing a second end of a drive shaft through a motor mount andthrough the hub and the connector so that the second end of the driveshaft engages with the impeller, a first end of the drive shaft beingsecured to the motor mount; and rotating the motor mount so as to rotatethe drive shaft that in turn rotates the impeller.
 29. The method asrecited in claim 28, wherein the step of removably coupling therotational assembly to the housing comprises: inserting the rotationalassembly within an access formed on the housing; and clamping therotational assembly within the access so that the casing is fixedrelative to the housing and the hub can rotate relative to the housing.30. The method as recited in claim 28, further comprising inserting theimpeller within the compartment of a container.
 31. A mixing systemcomprising: an elongated tubular connector having an interior surfacebounding a passage extending between a first end and an opposing secondend; an impeller disposed at the second end of the tubular connector; anelongated drive shaft having a first end and an opposing second end, thesecond end of the drive shaft being passed through the passage of thetubular connector to engage with the impeller so that rotation of thedrive shaft facilitates concurrent rotation of the impeller and tubularconnector, the first end of the drive shaft being disposed outside ofthe passage of the tubular connector; means for securing the first endof the tubular connector to the drive shaft; means for selectivelyrotating the drive shaft.
 32. The mixing system as recited in claim 31,wherein the means for securing is mounted on the tubular connector andradially inwardly biases the tubular connector against the drive shaft.33. The mixing system as recited in claim 31, wherein the means forsecuring comprises a clamp mounted on the tubular connector.
 34. Themixing system as recited in claim 31, further comprising a containerhaving a compartment, the impeller being disposed within thecompartment.
 35. The mixing system as recited in claim 34, wherein thecontainer comprises a flexible liner having an open mouth, the connectorfreely extending through the open mouth.
 36. The mixing system asrecited in claim 35, further comprising a rigid support housing, theliner being at least partially disposed within the rigid supporthousing.
 37. The mixing system as recited in claim 31, wherein the meansfor selectively rotating the drive shaft.
 38. The mixing system asrecited in claim 31, wherein the means for selectively rotating thedrive shaft comprises: a housing; a motor mount disposed on the housingand having a passage extending therethrough; and a drive motor coupledwith the motor mount for selectively rotating the motor mount relativeto the housing, at least a portion of the drive shaft engaging the motormount such that rotation of the motor mount facilitates rotation of thedrive shaft.